Active Control System for Diesel Particulate Filter

ABSTRACT

An active control system for diesel particulate filter includes a particulate filter unit, at least one sensor, a control unit, and a bypass unit. The sensor is in fluid communication with the particulate filter unit and electrically connected with the control unit so that the sensor is able to communicate with the control unit regarding the pressure and temperature readings of the exhaust gas flow. The bypass unit is in fluid communication with the particulate filter unit while a control valve of the bypass unit is electrically connected with the control unit. The control unit is able to operate the control valve depending upon the pressure and temperature readings of the sensor so that the bypass unit can be activated for the exhaust gas flow, where the bypass unit decreases the particulate matter buildup within the particulate filter unit and eliminates high engine exhaust back pressure.

The current application claims a priority to the U.S. Provisional Patentapplication Ser. No. 61/937,022 filed on Feb. 7, 2014.

FIELD OF THE INVENTION

The present invention relates generally to exhaust emission reductionsystems for diesel engine exhaust streams that have diesel particulatefilters. More specifically, the present invention is an active controlsystem that reduces particulate matter buildup in the diesel particulatefilters while eliminating high engine exhaust back pressure.

BACKGROUND OF THE INVENTION

Diesel Particulate Filters (DPF's) used in the exhaust stream of adiesel engine are susceptible to plugging as a result of particulatematter coming from the engine exhaust under certain engine operatingconditions. One, but not the only, example of such an operatingcondition is during the engine start up when the DPF has not reached aminimum operating temperature, known as the activation temperature,necessary for it to burn off a portion of the accumulated particulatematter. If the DPF is subject to an exhaust flow while it is below itsactivation temperature for too many operating hours, the channels in theDPF can become plugged decreasing the efficiency of the DPF. A pluggedDPF may create engine exhaust back pressure, which exceeds the allowablespecifications for the diesel engine, resulting engine stalling orpossible damage to the engine. This disclosure provides a system toensure that the DPF is less likely to become plugged from an exhaust gasflow. Additionally, the present invention also ensures that the engineexhaust back pressure does not exceed beyond the allowable specificationof the diesel engine.

The present invention provides an active control system so that theexhaust gas flow for the diesel engine can be diverted into the presentinvention until the DPF reaches the activation temperature. Thediverting process for the exhaust gas flow is carried out through acontrol unit as the pressure or temperature across the DPF is determinedthrough a sensor and compared with a preset value of the control unit.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of the present invention, showing the firstconfiguration of the at least one pressure sensor.

FIG. 2 is a side view of the present invention, showing the firstconfiguration of the at least one pressure sensor.

FIG. 3 is a side view of the present invention, showing the firstconfiguration of the at least one pressure sensor and the off-positionof the control valve.

FIG. 4 is a side view of the present invention, showing the firstconfiguration of the at least one pressure sensor and the on-position ofthe control valve.

FIG. 5 is a side view of the present invention, showing the secondconfiguration of the at least one pressure sensor and the off-positionof the control valve.

FIG. 6 is a side view of the present invention, showing the secondconfiguration of the at least one pressure sensor and the on-position ofthe control valve.

DETAIL DESCRIPTIONS OF THE INVENTION

All illustrations of the drawings are for the purpose of describingselected versions of the present invention and are not intended to limitthe scope of the present invention.

The present invention is an active control system for a diesel exhaustsystem so that the particulate filter of the diesel exhaust system isable to efficiently function with a minimum amount of particulate matterbuildup. As a result of minimum particulate matter buildup, the presentinvention also eliminates unnecessary back pressure of the exhaustsystem that can damage the engine. The present invention comprises aparticulate filter unit 1, at least one pressure sensor 6, a controlunit 9, and a bypass unit 10. The general configuration of the presentinvention is shown In FIG. 1 and FIG. 2, where the at least one pressuresensor 6 is in fluid communication with the particulate filter unit 1while the at least one pressure sensor 6 electrically connects with thecontrol unit 9. The bypass unit 10 is also in fluid communication withthe particulate filter unit 1 through a diverter duct 15 and a returnduct 16 of the bypass unit 10. Additionally, the bypass unit 10 iselectrically connected with the control unit 9 so that the control unit9 is able to control the generated exhaust gas with respect to theparticulate filter unit 1 and the bypass unit 10.

The particulate filter unit 1 generally reduces particle emissions inthe generated exhaust gas. The details of how the particulate filterunit 1 reduces amount of particle emissions are known to those withordinary skill in the art and are not discussed further herein. Inreference to FIG. 3-6, the particulate filter unit 1 comprises a housing2, an exhaust inlet 3, an exhaust outlet 4, and a diesel particulatefilter (DPF) 5. More specifically, the exhaust inlet 3 and the exhaustoutlet 4 are in fluid communication with the housing 2 as the exhaustinlet 3 and the exhaust outlet 4 are oppositely positioned of each otheracross the housing 2. The exhaust inlet 3 generally allows the generatedexhaust gas to flow into the housing 2 while the exhaust outlet 4discharges the purified exhaust gas from the housing 2. The purificationof the generated exhaust gas is completed through the DPF 5, where theDPF 5 can be a single filter or a plurality of filters. Morespecifically, the DPF 5 is internally connected to the housing 2 in sucha way that the DPF 5 is positioned in between the exhaust inlet 3 andthe exhaust outlet 4. As a result, the generated exhaust gas that entersinto the housing 2 is purified through the DPF 5 and then dischargedthrough the exhaust outlet 4 as purified exhaust gas when the DPF 5 isat the activation temperature.

When the DPF 5 is at the activation temperature, the particulate filterunit 1 is able to efficiently burn off the particulate matter thataccumulates within the DPF 5. However, when the DPF 5 is below theactivation temperature, the particulate matter builds up within the DPF5 as the particulate matter buildup negatively affects the functionalityof the DPF 5. More specifically, the efficiency of the DPF 5 drasticallyreduces within the exhaust system due to the particulate matter buildup,resulting in high back pressure within the exhaust system. The bypassunit 10, which decreases the high back pressure from the exhaust system,comprises at least one at least one control valve 11 in addition to thediverter duct 15 and the return duct 16. In reference to FIG. 4 and FIG.6, bypass unit 10 is in fluid communication with the particulate filterunit 1 so that the present invention is able to divert the generatedexhaust gas away from the DPF 5 in the event that the DPF 5 is below theactivation temperature. More specifically, the diverter duct 15 is influid communication with the exhaust inlet 3 so that the generatedexhaust air can be diverted into the bypass unit 10. The at least onecontrol valve 11 is in fluid communication with the diverter duct 15opposite of the exhaust inlet 3 as the flow of the generated exhaust gasis controlled through the at least one control valve 11. Morespecifically, the at least one control valve 11 is in fluidcommunication with the diverter duct 15 through an input channel 12 ofthe at least one control valve 11. The return duct 16 is in fluidcommunication with the at least one control valve 11 opposite of thediverter duct 15. More specifically, the at least one control valve 11is in fluid communication with the return duct 16 through an outputchannel 14 of the at least one control valve 11. In order to completethe bypass unit 10, the return duct 16 is in fluid communication withthe exhaust outlet 4 opposite of the at least one control valve 11. Inreference to FIG. 3-6, at least one control valve 11 further comprisesan actuator 13, where the actuator 13 is operatively coupled to the atleast one control valve 11. The actuator 13 allows the at least onecontrol valve 11 to operate in between an off-position and anon-position as the actuator 13 is electrically connected to the controlunit 9.

Depending on the amount of generated exhaust gas of the presentinvention, the bypass unit 10 can comprise multiple control valves 11 aseach of the control valves 11 is control by the respective actuator 13.The input channel 12 and the output channel 14 of each of the controlvalves 11 are able to jointly connect with the diverter duct 15 and thereturn duct 16 respectively so that the control valves 11 are able tomeet the increase amount of generated exhaust gas within the presentinvention.

The at least one pressure sensor 6 of the present invention can comprisedifferent configurations as a sample reading measured from the at leastone pressure sensor 6 is either an upstream pressure value or anupstream pressure value and a downstream pressure value. A preset valuethat is entered by the user of the control unit 9 is required for thefunctionality of the bypass unit 10 and is determined based on theallowable exhaust gas back pressure listed in the engine manufacturer'sspecifications.

In reference to FIG. 3-4, a first configuration of the at least onepressure sensor 6, the at least one pressure sensor 6 utilizes the inletpressure sensor 7 and the outlet pressure sensor 8 to measure the samplereadings. The inlet pressure sensor 7 is in fluid communication with theexhaust inlet 3 and positioned adjacent to the housing 2 so that theinlet pressure sensor 7 is able to measure the generated exhaust gaspressure before the generated exhaust gas is entered into the DPF 5. Theoutlet pressure sensor 8 is in fluid communication with the exhaustoutlet 4 and positioned adjacent to the housing 2, where the outletpressure sensor 8 is able to measure the generated exhaust gas pressureafter the generated exhaust gas is existed from the DPF 5. The inletpressure sensor 7 and the outlet pressure sensor 8 are electricallyconnected to the control unit 9 so that the inlet pressure sensor 7 andthe outlet pressure sensor 8 are able to send out the generated exhaustgas pressure before the DPF 5 and after the DPF 5 as the sample readingsto the control unit 9 respectively. More specifically, the inletpressure sensor 7 provides the upstream pressure value while the outletpressure sensor 8 provides the downstream pressure value to the controlunit 9. Then the control unit 9 calculates a sample value from theupstream pressure value and the downstream pressure value to determinethe pressure-gradient value across the DPF 5. The pressure-gradientvalue is then compared with the preset value so that the control unit 9is able to determine that the bypass unit 10 needs to be activated ornot. If the pressure-gradient value exceeds the preset value of thecontrol unit 9, the at least one control valve 11 is switched into theon-position from the off-position through the actuator 13. Once the atleast one control valve 11 is at the on-position, a portion of thegenerated exhaust gas flows through the diverter duct 15 and into theinput channel 12 while the other portion of the generated exhaust gasflows into the exhaust inlet 3. The generated exhaust gas within the atleast one control valve 11 is then able to flow into the return duct 16through the output channel 14. Then the return duct 16 discharges thegenerated exhaust gas of the bypass unit 10 into the exhaust outlet 4.Once the pressure-gradient value falls below the preset value, the atleast one control valve 11 is switched into the off-position from theon-position through the actuator 13 and the control unit 9.

In reference to FIG. 5-6, a second configuration of the at least onepressure sensor 6, the at least one pressure sensor 6 utilizes only theinlet pressure sensor 7 to measure the sample readings. The inletpressure sensor 7 is in fluid communication with the exhaust inlet 3 andpositioned adjacent to the housing 2 so that the inlet pressure sensor 7is able to measure the generated exhaust gas pressure before thegenerated exhaust gas is entered into the DPF 5. The inlet pressuresensor 7 is electrically connected to the control unit 9 so that theinlet pressure sensor 7 is able to send out the generated exhaust gaspressure as the sample reading to the control unit 9. More specifically,the inlet pressure sensor 7 provides the upstream pressure value to thecontrol unit 9. Then the control unit 9 calculates the sample value fromthe upstream pressure value to determine the inlet pressure value of theDPF 5. The preset value entered by the user of the control unit 9 thatis required for the functionality of the bypass unit 10 is determinedbased on the allowable exhaust gas back pressure listed in the enginemanufacturer's specifications. The preset value is then compared withthe sample value so that the control unit 9 is able to determine thatthe bypass unit 10 needs to be activated or not. If the sample valueexceeds the preset value of the control unit 9, the at least one controlvalve 11 is switched into the on-position from the off-position throughthe actuator 13. Once the at least one control valve 11 is at theon-position, a portion of the generated exhaust gas flows through thediverter duct 15 and into the input channel 12 while the other portionof the generated exhaust gas flows into the exhaust inlet 3. Thegenerated exhaust gas within the at least one control valve 11 is thenable to flow into the return duct 16 through the output channel 14. Thenthe return duct 16 discharges the generated exhaust gas of the bypassunit 10 into the exhaust outlet 4. Once the sample value from theupstream pressure value reaches the preset inlet pressure value, the atleast one control valve 11 is switched into the off-position from theon-position through the actuator 13 and the control unit 9.

Additionally, the present invention may comprise an inlet temperaturesensor and an outlet temperature sensor, where the inlet temperaturesensor and the outlet temperature sensor can be jointly or individuallyutilized in conjunction with the at least one pressure sensor 6. In afirst alternative embodiment, the present invention utilizes the inlettemperature sensor, where the inlet temperature sensor is in fluidcommunication with the exhaust inlet 3. Then the control unit 9 is ableto measure the temperature of the generated exhaust gas through theinlet temperature sensor as the inlet temperature sensor is electricallyconnected with the control unit 9. In a second alternative embodiment,the present invention utilizes the outlet temperature sensor, where theoutlet temperature sensor is in fluid communication with the exhaustoutlet 4. Then the control unit 9 is able to measure the temperature ofthe purified exhaust gas or the generated exhaust gas that exists fromthe DPF 5 before the activation temperature through the outlettemperature sensor as the outlet temperature sensor is electricallyconnected with the control unit 9. In a third alternative embodiment,the present invention utilizes the inlet temperature sensor and theoutlet temperature sensor, where the inlet temperature sensor and theoutlet temperature sensor are in fluid communication with the exhaustinlet 3 and the exhaust outlet 4 respectively. Then the control unit 9is able to measure the temperature of the generated exhaust gas and thepurified exhaust gas or the generated exhaust gas that exits from theDPF 5 through the inlet temperature sensor and the outlet temperaturesensor as the inlet temperature sensor and the outlet temperature sensorare electrically connected with the control unit 9. The control unit 9can then use an algorithm that takes into account exhaust temperatureand pressure to control the operation of the bypass unit 10. Thealgorithm calculates the loading of particulate matter in the DPF 5based on the long term temperature and pressure from the sensors. Whenthe algorithm determines that the loading of particulate matter in theDPF 5 is too high the bypass unit 10 opens.

Although the invention has been explained in relation to its preferredembodiment, it is to be understood that many other possiblemodifications and variations can be made without departing from thespirit and scope of the invention as hereinafter claimed.

What is claimed is:
 1. An active control system for diesel particulatefilter comprises: a particulate filter unit; at least one pressuresensor; a control unit; a bypass unit; the particulate filter unitcomprises a housing, an exhaust inlet, an exhaust outlet, and a dieselparticulate filter (DPF); the bypass unit comprises at least one controlvalve, a diverter duct, and a return duct; the at least one pressuresensor being in fluid communication with the particulate filter unit;the at least one pressure sensor being electrically connected with thecontrol unit; the bypass unit being in fluid communication with theparticulate filter unit through the diverter duct and the return duct;and the at least one bypass unit being electrically connected with thecontrol unit.
 2. The active control system for diesel particulate filteras claimed in claim 1 comprises: the exhaust inlet and the exhaustoutlet being in fluid communication with the housing; the exhaust inletand the exhaust outlet being oppositely positioned of each other acrossthe housing; the DPF being internally connected to the housing; and theDPF being positioned in between the exhaust inlet and the exhaustoutlet.
 3. The active control system for diesel particulate filter asclaimed in claim 1 comprises: the diverter duct being in fluidcommunication with the exhaust inlet; the at least one control valvebeing in fluid communication with the diverter duct opposite of theexhaust inlet; the return duct being in fluid communication with the atleast one control valve opposite of the diverter duct; and the returnduct being in fluid communication with the exhaust outlet opposite ofthe at least one control valve.
 4. The active control system for dieselparticulate filter as claimed in claim 3 comprises: the at least onecontrol valve comprises an input channel and an output channel; the atleast one control valve being in fluid communication with the diverterduct through the input channel; and the at least one control valve beingin fluid communication with the return duct through the output channel.5. The active control system for diesel particulate filter as claimed inclaim 1 comprises: the at least one control valve comprises an actuator;the actuator being operatively coupled to the control valve; and theactuator being electrically connected to the control unit.
 6. The activecontrol system for diesel particulate filter as claimed in claim 1comprises: the at least one pressure sensor comprises an inlet pressuresensor and an outlet pressure sensor; the inlet pressure sensor being influid communication with the exhaust inlet adjacent to the housing; theoutlet pressure sensor being in fluid communication with the exhaustoutlet adjacent to the housing; and the inlet pressure sensor and theoutlet pressure sensor being electrically connected with the controlunit.
 7. The active control system for diesel particulate filter asclaimed in claim 1 comprises: the at least one pressure sensor comprisesan inlet pressure sensor; the inlet pressure sensor being in fluidcommunication with the exhaust inlet adjacent to the housing; and theinlet pressure sensor being electrically connected with the controlunit.
 8. An active control system for diesel particulate filtercomprises: a particulate filter unit; at least one pressure sensor; acontrol unit; a bypass unit; the particulate filter unit comprises ahousing, an exhaust inlet, an exhaust outlet, and a diesel particulatefilter (DPF); the bypass unit comprises at least one control valve, adiverter duct, and a return duct; the at least one pressure sensor beingin fluid communication with the particulate filter unit; the at leastone pressure sensor being electrically connected with the control unit;the exhaust inlet and the exhaust outlet being in fluid communicationwith the housing; the diverter duct being in fluid communication withthe exhaust inlet; the at least one control valve being in fluidcommunication with the diverter duct opposite of the exhaust inlet; thereturn duct being in fluid communication with the at least one controlvalve opposite of the diverter duct; the return duct being in fluidcommunication with the exhaust outlet opposite of the at least onecontrol valve; and the at least one bypass unit being electricallyconnected with the control unit.
 9. The active control system for dieselparticulate filter as claimed in claim 8 comprises: the exhaust inletand the exhaust outlet being oppositely positioned of each other acrossthe housing; the DPF being internally connected to the housing; and theDPF being positioned in between the exhaust inlet and the exhaustoutlet.
 10. The active control system for diesel particulate filter asclaimed in claim 8 comprises: the at least one control valve comprisesan input channel and an output channel; the at least one control valvebeing in fluid communication with the diverter duct through the inputchannel; and the at least one control valve being in fluid communicationwith the return duct through the output channel.
 11. The active controlsystem for diesel particulate filter as claimed in claim 8 comprises:the at least one control valve comprises an actuator; the actuator beingoperatively coupled to the control valve; and the actuator beingelectrically connected to the control unit.
 12. The active controlsystem for diesel particulate filter as claimed in claim 8 comprises:the at least one pressure sensor comprises an inlet pressure sensor andan outlet pressure sensor; the inlet pressure sensor being in fluidcommunication with the exhaust inlet adjacent to the housing; the outletpressure sensor being in fluid communication with the exhaust outletadjacent to the housing; and the inlet pressure sensor and the outletpressure sensor being electrically connected with the control unit. 13.The active control system for diesel particulate filter as claimed inclaim 8 comprises: the at least one pressure sensor comprises an inletpressure sensor; the inlet pressure sensor being in fluid communicationwith the exhaust inlet adjacent to the housing; and the inlet pressuresensor being electrically connected with the control unit.
 14. An activecontrol system for diesel particulate filter comprises: a particulatefilter unit; at least one pressure sensor; a control unit; a bypassunit; the particulate filter unit comprises a housing, an exhaust inlet,an exhaust outlet, and a diesel particulate filter (DPF); the bypassunit comprises at least one control valve, a diverter duct, and a returnduct; the at least one pressure sensor being in fluid communication withthe particulate filter unit; the at least one pressure sensor beingelectrically connected with the control unit; the exhaust inlet and theexhaust outlet being in fluid communication with the housing; thediverter duct being in fluid communication with the exhaust inlet; theat least one control valve being in fluid communication with thediverter duct opposite of the exhaust inlet; the return duct being influid communication with the at least one control valve opposite of thediverter duct; the return duct being in fluid communication with theexhaust outlet opposite of the at least one control valve; the at leastone control valve comprises an actuator; the actuator being operativelycoupled to the control valve; and the actuator being electricallyconnected to the control unit.
 15. The active control system for dieselparticulate filter as claimed in claim 14 comprises: the exhaust inletand the exhaust outlet being oppositely positioned of each other acrossthe housing; the DPF being internally connected to the housing; and theDPF being positioned in between the exhaust inlet and the exhaustoutlet.
 16. The active control system for diesel particulate filter asclaimed in claim 14 comprises: the at least one control valve comprisesan input channel and an output channel; the at least one control valvebeing in fluid communication with the diverter duct through the inputchannel; and the at least one control valve being in fluid communicationwith the return duct through the output channel.
 17. The active controlsystem for diesel particulate filter as claimed in claim 14 comprises:the at least one pressure sensor comprises an inlet pressure sensor andan outlet pressure sensor; the inlet pressure sensor being in fluidcommunication with the exhaust inlet adjacent to the housing; the outletpressure sensor being in fluid communication with the exhaust outletadjacent to the housing; and the inlet pressure sensor and the outletpressure sensor being electrically connected with the control unit. 18.The active control system for diesel particulate filter as claimed inclaim 14 comprises: the at least one pressure sensor comprises an inletpressure sensor; the inlet pressure sensor being in fluid communicationwith the exhaust inlet adjacent to the housing; and the inlet pressuresensor being electrically connected with the control unit.